This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The purpose of this study is to demonstrate Fluorescent modulated imaging (fMI) via the quantitative and qualitative measurement of fluorophore phantoms. Fluorescent perturbations with various spatial and depth profiles in phantoms will be investigated. Qualititatively, the ability for spatial localization of the fluorophore. Quantitatively, the ability to measure fluorophore concentration as well as concentration and pH independent fluorophore metrics such as quantum yield will be investigated. Finally, tomographic reconstruction algorithms will be developed in parallel.